atonic writings many detached discussions in which the matter of the
categories is touched upon. Special terms also are anticipated at
various times, e.g. [Greek: poiotes] in the _Theaetetus_, [Greek:
poiein] and [Greek: paschein] in the _Gorgias_, and [Greek: pros ti]
in the _Sophist._[3] But there does not seem to be anything in Plato
which one could say gave occasion directly and of itself to the
Aristotelian doctrine; and even when we take a more comprehensive view
of the Platonic system and inquire what in it corresponds to the
widest definition of categories, say as ultimate elements of thought
and existence, we receive no very definite answer. The Platonic
dialectic never worked out into system, and only in two dialogues do
we get anything like a list of ultimate or root-notions. In the
_Sophist_, Being, Rest and Motion ([Greek: tho on autho kahi stasis
kahi kinesis]) are laid down as [Greek: megista ton genon].[4] To
these are presently added the Same and the Other ([Greek: tauthon kai
thateron]), and out of the consideration of all five some light is
cast upon the obscure notion of Non-Being [Greek: (to mhe on)]. In the
same dialogue (262 seq.) is found the important distinction of [Greek:
onoma] and [Greek: rhema], noun and verb. The _Philebus_ presents us
with a totally distinct classification into four elements--the
Infinite, the Finite, the Mixture or Unity of both and the Cause of
this unity ([Greek: tho apeiron, tho peras, he summixis, he aitia]).
It is at once apparent that, however these classifications are related
to one another and to the Platonic system, they lie in a different
field from that occupied by the Aristotelian categories, and can
hardly be said to have anything in common with them.

Aristotle.

The Aristotelian doctrine is most distinctly formulated in the short
treatise [Greek: Kategoriai], which generally occupies the first place
among the books of the _Organon_. The authenticity of the treatise was
doubted in early times by some of the commentators, and the doubts
have been revived by such scholars as L. Spengel and Carl Prantl. On
the other hand, C.A. Brandis, H. Bonitz, and Ed. Zeller are of opinion
that the tract is substantially Aristotle's. The matter is hardly one
that can be decided either _pro_ or _con_ with anything like
certainty; but this is of little moment, for the doctrine of the
categories, even